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C. J. MELLIN. Y EMERGENCY VALVE DEVICBAFOR GOMPOUND ENGINES.

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ns co. rumour UNITED] STATES *PATENT Critica CARL JIMEL'LIN, CERICHMOND, VIRGINIA, ASSIGNORIIO TI'IE RICHMOND LOCOMCTIVE A-ND MACHINE IVORKS, OF SAME PLACE.

EMERGENCY-VALVEVDEVICE FOR COMPOUND ENGINES.

SPECIFICATION forming part of Letters Patent N 0. 589,184, dated August 31, 1 897.

Application nea Decembr 12,1895. semina 571,859. (Nomea-,1.)

T o @ZZ whom/ t may concern:

Be it known that I, CARL J. MELLIN, a citizen of the United `States, and a resident of Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Intercepting and Emergency Valve Devices for Compound Engines, of. which the following `is a specification.

My invention consists in a construction whereby the force employed to open the emergency-Valve is utilized also for closing the intercepting-valve in a way to insurev more prompt and certain action of the intercept- 1 5 ing-valve and the live steam admittedto the low-pressure cylinder is madeto close the emergency-valve earlier than it can be closed by the high-pressure exhaust, as hereinafter fu-lly described, reference being made to the 2o accompanying drawings, in which- Figure l is a longitudinal sectional eleva.

tion of my improved valveapparatus, the intercepting-valve being open and the emergency-valve closed', as in normal compound z 5 operation of the engine; and Fig. 2 is a-similar section Withthe intercepting-valve closed and the emergency-valve open, as when working live steam direct in both cylinders. Fig. 3 is a detail in"section on line :r Figs. l

3o and 2.

A represents the valve-case, in which is the receiving-chamberb for the exhaust-steam from thev high-pressure cylinder and the delivery-chamber c for said steam to the low- 3 5 pressure cylinder, between which chamber is the communicating passage d, with the surrounding seat e, to which the interceptingvalve f is tted for closing said passage vwhen live steam is to be used directly in the low- 4o pressure cylinder.

The valve f is fitted to a holloT stem g, to which the piston 7L is attached, in the dashpot case t' on the cover j of one end of the valve-case A, and on an extension k of said stem, beyond piston it, is another piston Z,

working in a cylinder m, formed in an extension of the cover n of the dash-pot t', said piston being screwed on the rod and forming a check-nut to the piston h, which is also screwed on. The notches mare to make iiat 5o faces for the application of al Wrench for screwing the piston. l

A sleeve g2 is fitted on the rod g and within a cylinder p for a valve to control the admission of the live steam for direct action in the low-pressure cylinderand for a means of closing the intercepting-valve preparatory to such direct action. The said sleeve takes effecten the valve by the shoulder at q, and it is impelled bythe action of the live steam 6o on the shoulder s of i'tshead t, the steam beingadmitted at the port u, which is always Aopen for admission of the steam when the throttle-valve is open. In closing` the intercepting-valve the shoulder S of piston-headt passes'oiit of lthe end of cylinder p to 'open for admission of the steam, the arrangement being suchthat the edgeof valve f enters the recess of seatl e slightly'T before the said opening takes p'lacetoprevent escape of steam so 7o admitted past saidvalve f.

When the intercepting-valve opens and shoulder s. of head -t' is kforced back within cylinder p, live steam is shut off just before valve f escapes from the recess of valve-seat e. The limit of the opening of valve f is determined by a shoulder c in the cylinder p, back of port u, where the bore is reduced for overbalancing effectv of steam on shoulders and fora seat for said shoulder s to so limit 8o the opening.`

The neck w ofthe sleeve or admissionvalve is proportioned in size to the size of the larger part of the cylinder p, which it occupies when open to limit the amount of steam admitted, so that pressure will not rise too high in the low-pressure cylinder, and so that when the movement of the engine increases sufficiently for changing to compound action the pressure of the live steam Vin the loiv- 9o pressure cylinder will fall to a degree that will be overbalancedrby' the pressure of eX- haust-steam in chamber b from the highpressure cylinder which will automatically open the intercepting-valve and cause resumption of normal action.

As thus far described the apparatus is substantially same as is now in use, and emergency-valves have also been used in various arrangements together with them for enablin g continued use of live steam for a longer time and for changing from compound to direct action while running, and l do not claim such apparatus broadly.

The emergency-valve is represented at a opposite to the intercepting-valve f and in line with it axially. It opens communication from chamber l) through wall c' into chamber d', from which there is free exhaust by the passage c. The stem f of this valve eX- tends entirely through the hollow stem g of the intercepting-valve and has a piston g attached to its extremity in a cylinder h' in the cover of cylinder m. Steam or other pressure is admitted through pipe 'i' to cylinder h' between pistons l and g/ when at the will of the en gineer the emergency-valve is to be opened. lt acts on both pistons and thus sets the intereepting-valve in motion for closing at the same time that it opens the emergency-valve and effects the change from compound to direct action more promptly.

The hollow stem g of the intercepting-valve has a port jg, which admits live steam into the bore of said stem when live steam enters the low-pressure side at starting, and stem f of the emergency-Valve has a shoulder 7a in said bore whereon such steam acts, so as to close the emergency-valve before the exhaust comes from the high-pressure side, and thus effects earlier closing and saves some waste of steam.

I claim as my inventionl. The combination in a compound en gine, of the intercepting-valve having a hollow stem, emergency-valve having its stem eX- tended through the hollow stem of the intercepting-valve, casings for, and passages controlled by said valves, a piston attached to each stem respectively, a cylinder for said pistons andan admission-portintermediately of said pistons fora motive fluid substantially as described.

2. The combination in a compound engine, of the intercepting-valve, emergency-valve easings for, and passages controlled by said Valves, and means whereby live steam admitted to the low-pressure cylinder7 also takes effect on the emergency-valve for closing it prior to the action of the high-pressure eX- haust on said emergency-valve substantially as described.

3. The combination in a compound engine, of the intercepting-valve, emergency-valve casings for, and passages controlled by said Valves, the bored stem of the intercept-ingvalve, and shouldered stem of the emergencyvalve said stem of the emergency-valve subject to live steam admitted to the low-pressure cylinder for closing said emergency-Valve prior to the action ot' the high-pressure exhaust on said emergeneyvalve substantially as described.

4. The combination in a compound engine, of the intercepting-valve, emergency-valve casings for and passages controlled by said valves, bored stem of the intercepting-valve, stem of the emergency valve extending through the stem ot the intercepting-valve, piston on the extremity of the intereeptingvalve stem, piston on the stein of the emergency-valve, cylinder for said pistons and the motor-luid-admission port intermediately of said pistons substantially as described.

5. 'lhe combination in a compound engine, of the intei'ceptingvalve, emergency-valve easings for, and passages controlled by said valves, stem of the emergeney-valve extending through the stem of the intercepting- Valve,dashpot for the intercepting-valve,piston on the extremity of the intercepting-valve stem, piston on the extremity ot' the emergency-valve, cylinder for said pistons, and the motor-Huid-admission port intermediate of said pistons substantially as described.

G. The combination ofanintercepting-valve normally held open by the exhaust-steam from the high-pressure cylinder and provided with means for closing it in the absence of said eX- haust-steal'n, an exhaustvalve for relieving said intercepting-valve of said exhaust-steam, and an air dash-pot located in the head of the casingol" the intercepting-valve substantially as described.

Signed at New York city, in the county and State of New York, this 26th day of October, A. D. 1895.

cARL J. MELUN.

Witnesses W. J. MORGAN, A. P. THA'YER. 

